Walnut is a very important fruit type in terms of health and nutrition. Generally, walnuts contain 3.5% water, 15-30% protein, 55-77% fat, 1.5-3% ash and 5-15% carbohydrate (cellulose by weight). In addition, the fruit of walnut is rich in minerals such as Ca, P, Mg, Fe, Na, K as well as vitamins A, B1, B2, B6, C. 1 kg of walnuts provides approximately 7,000 calories of energy. Walnuts are consumed in many different ways. It is consumed as a snack, in the cake and biscuit industry, in the perfume industry, in the production of jam, halva, in the paint, tannin, plastic and rubber industry, as an oil, in the pharmaceutical industry, in the production of sausage, samsa, and fruit pulp. In addition, walnut is one of the most sought-after materials in carving because of its extremely precious timber.
HERBAL PROPERTIES OF WALNUT
3.1. Tree Structure and Root:
- Walnuts grow rapidly and grow up to 25-40 m and a tree can cover an area of 300-500 m².
- Walnut trees generally have a “flat” crown shape. Crown shape is also seen in “semi-upright and upright” structure.
- Walnuts have pile root and capillary roots can be found in abundance. Roots can grow up to 3-5 m deep.
3.2. Trunk and Branches
- Branching in the trunk generally starts at a height of 1-2 m from the soil surface.
- The body circumference can develop up to 5-6 m.
- In the youth, the smooth surface and silvery colored body becomes darker (gray-black) in very advanced ages, and longitudinal cracks occur in the shell.
- Shoots are glabrous, bright olive green or dusky in color.
3.3 Leaves and Eyes
- Leaf; It consists of 5-13 leaflets arranged opposite each other on a long stalk.
- Leaflets are wide elliptical and full-edged. Their tips are pointed and their length varies between 6-12 cm. The color is bright green and they are arranged spirally on the body.
- The eyes are at the ends of the branches and leaf seats (1-3 pieces) and they are dark brown in color. Three eyes are large. The larger one of the eyes in the leaf axils picks up and creates the wood branch.
- There are female flowers at the tips of the shoots that are formed only from the tip buds of the unproductive varieties. However, female flowers occur in almost all buds (including leaf buds) of fertile varieties.
3.4. Flower Structure and Fertilization Biology
Flowers in walnuts are monoic in nature. In other words, male and female flowers are on the same tree but in different places. Pollination in walnuts occurs with the help of wind.
- WALNUT’S ECOLOGICAL (CLIMATE AND SOIL) REQUIREMENTS
Walnuts are cold enough to meet the need for cooling in winter and spring; In the spring and summer months, they want warm enough (25-35⁰C) to ensure normal growth and maturation. Summer temperatures higher than 40 ° C may cause burns in the walnut green shell and shrinkage in the walnut. Although the walnut plant is generally damaged in temperatures lower than -20 C, there are varieties that can withstand up to -40 C. In addition, temperatures below -1⁰C in the bud period, -3⁰C in the full bloom period and -1⁰C in the small green fruit period can be harmful. Factors such as the degree of low temperature, the falling speed, and the duration of the cold play an important role. The cooling requirement of walnut varieties varies between 500-2000 hours under + 7.2⁰C. For a regular product, the chilling requirement of walnuts must be met.
In terms of walnut cultivation, a total annual precipitation of at least 500 mm is sufficient, but it is important that this precipitation is regular. In order for the fruits to develop normally, there should be sufficient water in the soil in summer. In addition, rains and excessive winds during the flowering period may cause a negative situation, especially in terms of pollination-fertilization.
Walnut has a strong root system that can go down to 2-4 m depth. Therefore, problems may arise in terms of aquaculture in places where soil depth is low. In order to avoid problems in terms of cultivation, the depth of the soil should be at least 2 m and the soil should be permeable. Soil pH should be around 6-7 and there should be no alkalinity and salt problems in the soil. The soil should be well-drained, permeable, rich in organic matter and airy. The high water holding capacity of the soil is important for walnut cultivation. However, walnut is not a very selective fruit type in terms of soil.
- REPRODUCTION OF WALNUT
5.1. Generative (by Seed) Propagation
The daughter plants that occur in seed propagation do not possess almost any characteristics of the parent plant. For this reason, reproduction by seed in walnuts is not a preferred propagation method except for obtaining rootstock or seedlings and breeding studies, due to genetic expansion.
5.1.1. Features to Look for in Seeds
Walnuts to be used as seeds;
- Should be plump,
- Their development must be complete,
- It should be taken from healthy and well developed trees,
- Fruits damaged for any reason should not be used as seeds.
5.1.2. Folding Seeds
Storing in humidified environments in order to meet the cooling needs of the seeds, to remove the obstructing factors, to soften the seed coat, to increase the germination power of the embryo by facilitating the water and oxygen intake and to accelerate it is called folding. The general advantage of folding seeds is that early and regular germination is achieved by eliminating the effects of factors that inhibit seed germination.
The start of folding is determined according to the state of the soil in the place where the cultivation will take place.
Crates (such as fruit and vegetable crates) that can be easily carried by a person can be used in folding. After placing the gravel large enough to cover the holes on the bottom of these crates, folding sand (construction sand) is laid on it properly. Seeds are planted one by one on this sand. Then the seeds are covered with sand, and then one row of seeds and one row of sand continue until the casing is full. Folding process completeThe thickness of the sand to be put on top should be a little more than the others. After the container is filled, the sand is moistened with strainer buckets. Then, these folding crates can be used in cool basements, ordinary warehouses and so on. They are taken to such environments. The folding time of the seeds in walnuts varies between 60 and 90 days, depending on the variety. When the hard shell of the seed cracks and the root tip appears, folding is stopped. Seeds are sown in the soil to a depth twice their size. In order for seedlings to develop well after seed planting, care should be taken to irrigate the seedlings, especially weed removal. Cutting the pile roots during the resting period, a while before the removal of the decays, improves the fringe root formation and increases the retention success in staggering.
5.2. Vegetative Propagation
Walnuts, which cannot be reproduced by seeds due to genetic expansion, are propagated vegetatively. Although it is difficult to vaccinate in walnuts, the vegetative propagation method that maintains its validity today is propagation by grafting.
5.2.1. Vaccine Replication
220.127.116.11. Factors Affecting Vaccine Success
Temperature: The ambient temperature being between 23-30C increases the success of vaccination in walnuts.
Humidity: Humidity of the environment positively affects the success of vaccination.
The experience of the vaccinator : Since the success of vaccination in walnuts is generally lower than other fruit types, the experience and skill of the vaccinee is very important in vaccination success.
Materials used in the vaccine: The materials used must be of good quality. For example, the blade surface should be very smooth and very sharp to cut in one stroke. Preferably cotton thread or graft bite should be used to wrap the vaccine .
Pen: Healthy and well developed annual shoots are taken as cuttings. The untreated eyes (preferably between the 2nd and 5th eyes) on the pen are used in the vaccine. Cut pens must be kept in a humid environment during storage and vaccination.
Vaccination time:One of the most important factors that increase the success in vaccination is the time of vaccination, and it is the most appropriate time when the seedlings and the shoots to be taken from the vaccine leaves the bark easiest. The following method can be applied to determine the most appropriate time of vaccination; When the shell on the vaccination slide is removed, if the growth point remaining under the eye remains in the shell, it is time for this eye to be vaccinated. However, if the growth point remains in the exile, that is, in the wood tissue, it means that the vaccination time has passed for this eye. In this case, a gap occurs under the eye in the shell. When the vaccine is administered, the air in this space under the shell causes the vaccine eye and its surroundings to turn black and dry. Such eyes are not preferred for vaccination.is the time he mentions. In other words, when the crops start to be harvested in a region , it means when eye vaccinations can be made on walnuts for that region.
6.GARDENING AND ANNUAL MAINTENANCE WORKS
6.1. Setting Up a Garden
It is necessary to know the ecological characteristics of the region well before establishing a garden in walnut, which lives very long and is very difficult to reproduce by vaccination. Walnuts should not be grown in regions where winters are very extreme and constantly low temperatures prevail, and in places with extremely hot summers. Since walnuts have a strong root system that goes deep, the soil depth should be at least 2 to 2.5 m and there should be no impermeable layers. There should not be too much alkalinity and salinity problems in the soil of the area where the breeding will be done.
6.2. Variety selection
Dichogamy of male and female flowers at different times is common in walnuts. In this case, there are homogamous types and varieties whose male and female flowers mature at the same time, as well as varieties whose male flowers mature first (prot andry) and female flowers mature first (protogyny). Therefore, when establishing a walnut garden, either a variety with male and female flowers maturing at the same time (homogamy) or a mixed planting with more than one variety whose male and female flowers mature at the same time should be preferred.
Although the planting intervals vary according to ecological and maintenance conditions, the most ideal planting intervals in walnuts; It is 10 x 10 m, 10 x 8 m or 8 x 8 m.
Planting of the seedlings begins in the resting period (from the foliage) and continues until the eyes wake up. The seedlings should be disassembled very carefully and care should be taken not to damage the roots. During planting, especially root pruning should be done on seedlings. Planting pits should be opened at least 60-70 cm wide and 80-100 cm deep. Saplings should be planted so that the grafting points remain above the ground and the pits should be filled with top soil in the garden. Life water should be given to the seedlings immediately after planting. After planting, considering the future timber situation, the sapling trunks should be cut approximately 1-1.5 m above the soil surface and the crownreminiscent pruning should be done. After that, the saplings should be tied to the props considering the prevailing winds in the region. In regions with hot and dry summers and low water resources, it would be appropriate to mulch with weed or grain stalks in order to prevent water loss after planting.
6.4. Soil cultivation
When the soil pans in the spring, a deep release is made. Tillage in this period is very important in terms of airing the soil as well as providing weed control. Tillage can be done in terms of weed control in the summer months. The version to be plowed in autumn is important in terms of penetrating and keeping rain and snow water in the soil. While cultivating the soil, care should be taken not to injure the roots.
Since walnut trees are large and widely branched, they have a wide leaf surface. For this reason, it is very important to provide sufficient water to walnuts with high water loss through perspiration.
For walnuts, it is very important to meet the water requirement during the spring development, fruit growth and filling periods. The lack of water during these periods will slow the growth and development and cause the fruits to not fill enough, so quality and yield decreases.
One of the most important points to be considered in irrigation is to ensure that the water reaches the effective root level. In the first years of walnuts, it is necessary to irrigate twice a week, considering the condition of the region and the water source. All kinds of water that is not contaminated with harmful factors such as chemical wastes can be used for watering walnuts.
Walnut is not a very sensitive plant in terms of fertilization if there is no extreme problem in the soil. However, due to its structure, the most important plant nutrient requirement may be nitrogen. According to the results of the soil analysis to be made, the nutrients missing in the soil should be given to the soil within a certain program.
Walnut trees form a large and large crown. However, these trees generally do not require too much pruning. In addition, it is beneficial to remove the dried and intertwined branches and to prune the spacers to allow light to easily enter the tree crown. Although the pin pruning system is generally applied as shape pruning in walnuts, the type and amount of pruning may also vary depending on the environment and the purpose of growing the trees.
- HARVEST AND AFTER
Harvesting of walnuts is considered to be the period when the walnut and green shell ripen. The period when the thick opens and leaves the hard shell is the ripening signs of the green shell. If the walnut is a sign of maturity; This is the period when the package texture between the walnut and the hard shell begins to turn brown. Often the green shell ripens later than the walnut. Harvesting at the time of the walnut maturity will increase the commercial value of the walnut due to the light color of the walnut in this period. However, very important quality losses may occur if the grower waits for the harvest time of the green bark to mature.
The climate can have a significant effect on the harvest time of walnuts. In areas with a cool climate, the ripening time of the walnut and the ripening time of the green shell usually coincide with the same period. High humidity resembles the opening of the green shell quickly . An important factor affecting the harvest time is the cultivated variety. For example, when harvested on time and correctly , varieties such as Ch andler have a light internal color.
Collecting the harvested fruits, separating the green peel and drying the fruits, etc. should be as quickly as possible to avoid quality losses. In the fruits that are under the sun, the fruits that remain on the green peel for a long time are damaged.
7.1. Harvest Methods:
Harvesting of walnuts is done by two methods, manually and mechanically. While the beating Turkey in walnut-shaped pole tree harvesting is done mechanically roads in the leading countries. During the harvest made in the form of beating trees, significant damages can occur, especially on the branches that will yield in the next year.
Mechanical harvesting; It is made by shaking the main branches of the tree or the tree trunk with various shakers and making the fruits fall from the tree to the ground.
In order to minimize quality losses after harvest, the green shell should be easily separated from the hard shell, that is, the fruits should be fried immediately. In some regions, covering the green shell with nylon, thick cloth and sacks in order to soften and remove it easily can cause significant quality losses. In some countries, roasting is done completely mechanically.
It is asked to come out as a whole for market value. If the harvested fruits are to be marketed internally, the walnuts are broken down before they dry (when they are moist). Thus, it is provided to come out in an easier way.
In our country, walnut crushing operations are generally carried out by women in places called as exhibition halls by hitting them with a hammer. After the crushing process, the walnuts are classified according to their color and subjected to packaging.
Fruits that will not be considered as walnuts, that is to be marketed as shelled, should be dried immediately after roasting. The drying process is very important for the storage life of walnuts. For this, the highest moisture levels required in shelled and kernel walnuts were determined by standards. For example, dried according to TSE; A moisture content of 8% is required for shelled walnuts and 5% for kernels.
In our country, walnuts are generally dried outside in the shade. In some regions, drying is done by keeping it under the sun for 7-10 days. This causes various quality losses such as darkening of the interior color. Therefore, this drying method is wrong. If there is no other drying option, at least drying should be done outside in shadow areas. In other words, fruits should not be dried under direct sunlight. However, in the countries that have a say in the world walnut production, drying is done completely by mechanical means. In mechanical drying processes, fruits are generally kept at 30-35C for 24 hours. Temperature rise above 40⁰C is undesirable in terms of internal quality.
7.4. Storage and Packaging:
Since walnuts are fruits with high fat content, storing them under appropriate conditions is especially important in terms of fat deterioration in the inner fruit. Therefore, walnuts can be stored at low temperatures (0-4⁰C) and in dry environments for a long time.
Packaging is a very important stage in the marketing of a product. For this reason, packaging with healthy materials appeals to consumers in terms of marketing both shelled and walnut. There is a clear difference between the appeal of mixed walnuts filled with large sacks and walnuts, all of the same color, packed in small weight. For example, it is very important for consumers to make and label the walnuts with vacuum-proof plastic bags that are not transparent to light.